JDWP: fix returned tag for ClassType.NewInstance

Bug: 25490662
Change-Id: I0c369f04342a60caef4f7462005804307a410d18
diff --git a/runtime/debugger.cc b/runtime/debugger.cc
index e523fbb..6e4b7a3 100644
--- a/runtime/debugger.cc
+++ b/runtime/debugger.cc
@@ -4069,13 +4069,15 @@
   if (is_constructor) {
     // If we invoked a constructor (which actually returns void), return the receiver,
     // unless we threw, in which case we return null.
-    result_tag = JDWP::JT_OBJECT;
+    DCHECK_EQ(JDWP::JT_VOID, result_tag);
     if (exceptionObjectId == 0) {
       // TODO we could keep the receiver ObjectId in the DebugInvokeReq to avoid looking into the
       // object registry.
       result_value = GetObjectRegistry()->Add(pReq->receiver.Read());
+      result_tag = TagFromObject(soa, pReq->receiver.Read());
     } else {
       result_value = 0;
+      result_tag = JDWP::JT_OBJECT;
     }
   }